MAGNETISM

MAGNETISM

Magnetism is a class of physical phenomena that includes forces exerted by magnets on other magnets.

MAGNETS

FOR EVERY NORTH, THERE IS A SOUTH

Every magnet has at least one north pole and one south pole.  By convention, we say that the magnetic field lines leave the North end of a magnet and enter the South end of a magnet. 

If you take a bar magnet and break it into two pieces, each piece will again have a North pole and a South pole.  If you take one of those pieces and break it into two, each of the smaller pieces will have a North pole and a South pole.  No matter how small the pieces of the magnet become, each piece will have a North pole and a South pole. 

S N S N S N

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A COMPASS USES A TINY MAGNET

WHICH CAN SWING ROUND.

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USING A COMPASS TO FIND DIRECTIONS A compass needle always points to

the Earth’s North Pole.

Some birds use the Earth’s magnetism to find directions.

NO MONOPOLES ALLOWED

It has not been shown to be possible to end up with a single North pole or a single South pole, which is a monopole ("mono" means one or single, thus one pole). 

Note: Some theorists believe that magnetic monopoles may have been made in the early Universe. So far, none have been detected.

S N

P.277 ½ crosswiseMake a table showing differences of

magnestism.Magnet Magnetic

CharacteristicsExamples

Ferromagnetic Material

Ferrimagnetic Material

Paramagnetic Material

Diamagnetic Material